The Fighting Foreign Illegal Seafood Harvests Act of 2026, or FISH Act, targets illegal fishing operations worldwide by establishing a comprehensive U.S. government response to combat illegal, unreported, and unregulated (IUU) fishing. The bill creates a publicly maintained list of foreign fishing vessels and their owners engaged in IUU fishing, which the Commerce Department will develop and update regularly, including vessel names, identification numbers, and the reasons they were listed. Foreign nationals who own or benefit from vessels on this IUU list will be barred from entering the United States and will have their existing visas revoked, though exceptions exist for humanitarian aid, law enforcement activities, and safety provisions. The legislation authorizes $10 million annually through fiscal year 2031 to implement the vessel list system, provides $2 million for a National Academies study on IUU fishing's economic impacts, extends National Sea Grant Program funding through 2032, and encourages the Coast Guard to increase boarding and inspection of suspected IUU fishing vessels. The bill also directs federal agencies to develop strategies for identifying seafood produced with forced labor, establish better data-sharing between agencies and states, and increase technical assistance to foreign nations to strengthen their fisheries management and combat IUU practices at their source.